They should try to fix it by controlling any ads before it was published. That's the only way they can stop fake ads from happening, or they could build a great AI to filter out fake ads. Seems difficult but not impossible.
1. They obviously can't have enough manual hands to do this. Algorithms get tricked easily, and as they say in the article, the scammers get better and are faster at evading the algorithms than anyone can handle.
2. FB wants money, if your ad passes the automated verification, they'll take your money.
3. Education is better than building better AI. Scammers are always ahead of the curve. Teach people how to avoid them and they take care of themselves.